Pirates of the Caribbean

Pirates of the Caribbean is a canon and multibillion-dollar franchise derived from a movie series, which was in turn derived from a Disney theme park ride. The fact that the series is good (or maybe just the first movie is good, depending on who you ask) is a small miracle, given that unlikely origin story. Various supplemental novels and games have been released as well.

It is set in an indeterminate time in the Golden Age of Piracy, in a universe where the myths and legends sailors tell are actually true. This includes things like ghost/zombie pirates, cursed Aztec gold, Davy Jones, the Kraken, the Edge of the World, and the Fountain of Youth.

Agents are considered specialized in a continuum when they have handled at least three missions in the canon. Most of these agents are also active/specialized in other continua. It is often not the agents who decide where their specialty lies, but the Flowers that keep assigning missions to them.